1. Field of the Invention
The present invention relates to a construction machine.
2. Description of the Background Art
In recent years, there has been developed a construction machine loaded with an SCR (Selective Catalytic Reduction) system in order to reduce NOx contained in exhaust gas. Specifically, there is known a construction machine provided with a reducing-agent tank for accommodating reducing agent such as urea water. In the construction machine, the reducing agent is added to exhaust gas for promoting reduction of NOx in the exhaust gas.
Japanese Unexamined Patent Publication No. 2011-012661 (Patent Literature 1) discloses a construction machine provided with an upper slewing body, on which a reducing-agent tank is loaded. The construction machine is further provided with a tool box for facilitating a supply operation of reducing agent into the reducing-agent tank from outside of the upper slewing body or maintenance of the reducing-agent tank. The tool box has an openable/closable cover member. The tool box is disposed on an outer portion of the upper slewing body to house the reducing-agent tank therein.
International Unexamined Patent Publication No. 2013/137169 (Patent Literature 2) discloses a construction machine provided with a first accommodation case defining an article accommodation space and a second accommodation case housing a reducing-agent tank therein.
The construction machine disclosed in Patent Literature 1, involving the requirement of the tool box to accommodate the reducing-agent tank in addition to a tool to be accommodated, permits the tool box to have only a reduced space for accommodating the tool box by the capacity of the reducing-agent tank. Besides, the tool in the tool box can exert an impact on a tank body of the reducing-agent tank, the tank body thus being likely to be damaged by the impact because it is made of a resin material for prevention of the tank body from rust due to urea.
On the other hand, the construction machine disclosed in Patent Literature 2, having both of the first and second accommodation cases, involves increase in the number of parts and cost. Furthermore, the entire construction machine has to be large-sized in order to secure an accommodation space for both of the two accommodation cases. The accommodation space may be reduced by vertical arrangement of the tanks; however, such vertical arrangement hinders an operator from easily accessing the case disposed at upper side from the ground, thus making a maintenance operation therefor difficult.